Research on Dynamic Selection Technology for Universal Segment Construction of Shield Tunnels

Universal segments are a widely used type of tunnel lining segments in shield tunneling. During construction, different assembly positions are selected to ensure that the assembled segments match the attitude of the shield machine, and that the segments at the tail of the shield are not squeezed during the tunneling process. In order to realize automatic selection of segment assembly points in the construction process and improve the quality of segment assembly, a dynamic selection method of general type segment assembly points was proposed. The spatial geometric relationship between the driving attitude of the shield machine and the attitude of the segment is solved by using the driving parameters of the shield machine. With the change of the shield tail clearance as the optimization control objective, the influence of the direction deviation between the shield tail plane and the end surface of the segment, the stroke difference of the propulsion cylinder and the point position of the segment assembly on the shield tail clearance is considered, and the optimization function of the dynamic selection point of the segment assembly is established. It can solve the difficult problem of segment point selection during shield construction. Taking the Jiangxinzhou Tunnel project in Nanjing as an example, MATLAB software was used to edit the optimization algorithm of segment point selection, and the predicted gap of the shield tail was in good agreement with the measured results, which effectively verified the feasibility of the method. Compared with the manual experience method, the gap deviation of shield tail is smaller after the point selection, which is conducive to improving the quality of segment assembly.